Like MassMOCA's children's gallery, which I also love, the museum assumes that children deserve and should see original artwork and that interactions should spring from that experience. Here's just a bit of what I observed.
First, an interactive done with something many of you have in your space where you store things you want to get rid of but don't ever get around to: an overhead projector. Children arranged shapes on the projector, they were projected big so they could see them--but also then, you could view it from the back, where hands and shapes were in a mysterious dance. What would happen next?